first-hand knowledge

I want to set the record straight based on firsthand knowledge.

But I have firsthand knowledge of these opinions as well.

His own horn playing gave him firsthand knowledge of how a chart should feel.

I do not have any personal or firsthand knowledge of those events.

"In less than a minute, I guarantee you will have firsthand knowledge."

He in turn derived from her some firsthand knowledge about Spanish music.

And I was given your name as someone who might have some firsthand knowledge of what's going on here.

Therefore, we have no firsthand knowledge of what happened there.

No firsthand knowledge is necessary for one to appreciate its wisdom.

I don't need firsthand knowledge of him to feel that his administration is taking the country in the wrong direction.